Emotional and social characteristics were studied in epileptic patients before and following unilateral left or right temporal lobe resection. Physiological events (skin conductance) and EEG measures were also monitored during select procedures. The research examined the role of the left and temporal lobe in emotional perception and expression, and how epilepsy alters these functions. Skin conductance responsivity (SCR) and levels (SCL) were monitored from patients following unilateral left or right temporal lobectomy, and normal subjects during a habituation procedure. Right temporal lobectomy (RTL) patients were less responsive to evocative stimuli and showed rapid habituation and extinction. In contrast, left temporal lobectomy (LTL) patients showed increased arousal and slowed habituation; electrodermal responses by normal subjects assumed a rate of change that was intermediary to the lobectomy groups. Unilateral temporal lobectomy, including the amygdala and varying portions of limbic structures did not produce hypoarousal, per se. Although RTL patients had relatively intact SCR resting levels these patients evinced rapid habituation whereas LTL remained hyperaroused. These data suggest that increased activation may follow left temporal injury and be associated with anxiety and depression. Right temporal lesions may produce inattention and hypoarousal that is activated by robust emotional changes and novelty. The personality style of LTL patients showed a reflective orientation that was self-denigrating and dysphoric. In contrast, RTL patients assumed a self-enhancing posture that was optimistic, euphoric and extrapersonally oriented.